The human tongue is located in the oral cavity, wherein various pathological microorganisms are also found. In addition, mouth saliva contains various defensive elements against foreign intruders. Ideally, the various microorganisms that inhabit the oral cavity are in mutual balance and symbiosis.
The surface of the tongue is not flat and has various protrusions and depressions, such as the areas of the foliate papilla, the circumvallate papilla, the fungiform papilla, and the filiform papilla. In some pathological situations, different infectious elements can penetrate these depressions, causing halitosis (offensive breath) as well as being a potential for the development of disease.
In addition to the topology of the tongue, with its various papillary elements, a further factor to be considered is the proximity and connection of the tongue to the nose, sinuses, tonsils, and uvula and throat area. This renders the tongue particularly susceptible to invasion of different microorganisms, including pathological microorganisms, in a situation of locus minoris resistenta.
Among groups of people who may be particularly susceptible to the development of pathological conditions, due to an imbalance between the various microorganisms in the oral cavity, are denture wearers, people taking antibiotics over a prolonged period of time, people with recurring chronic gum disease, people with tooth implants, and heavy smokers.
It has been found that most of the pathological microorganisms in the oral cavity are located on the root of the tongue, and that, notwithstanding the fact that various mouthwashes for reducing halitosis are available in the market, they do not provide an effective solution to this problem.
In the April 1964 edition of "THE DENTAL PRACTITIONER", it is suggested on page 313 that halitosis can be reduced by scraping the tongue. More recently, on Feb. 18, 1994, during a lecture to dental surgeons at the University of Tel Aviv, Professor Rosenberg suggested that, in order to clean the root of the tongue so as to eliminate, or at least substantially reduce, halitosis, it is desirable to brush the tongue root.
Toothbrushes are too large (high) to fit comfortably in the space between the soft palate and the tongue root, and they cannot therefore be used for brushing of the tongue root. Furthermore, any substantial reduction in the height of a toothbrush to a height which would enable it to be inserted comfortably between the soft palate and the tongue root would render it unsuitable for toothbrushing, and would therefor be undesirable.
Furthermore, conventional toothbrushes have elongated, relatively narrow heads which are substantially narrower than the tongue, their width being substantially the height of the teeth, and they are intended for a back-and-forth motion, along the longitudinal axis of the brush head. Accordingly, even if their height were such that they could be comfortably inserted between the tongue and the soft palate, a relatively large number of strokes would be required in order to cover the entire width of the tongue root, so this would not be an efficient manner of brushing the tongue root. Furthermore, this may lead to excessive irritation of the tongue root.
The described back-and-forth motion has a further disadvantage, in that it would result in repeated striking of the rear of the oral cavity, particularly the soft palate and the uvula, thereby causing discomfort and possibly leading to vomiting.
Use of a toothbrush for brushing of the tongue in a direction transverse to the longitudinal axis of the brush head would require the brush to be firmly held perpendicular to the tongue surface in a position which, when taking into account the brushing direction, is inherently unstable. Holding the brush in this position would thus be tiring, leading to inefficient brushing.
A number of patents deal with oral instruments for cleaning the tongue. U.S. Pat. No. 2,708,762 discloses an oral instrument including a toothbrush at one end, a pad including rubber massaging fingers at the other end thereof, and a tapered scraper blade in between.
U.S. Pat. No. 5,005,246 discloses a toothbrush having an integrally formed brush head with removable bristles for replacing the brush, and an elongate tongue scaler, including a tenon at one end, telescopically mounted in the brush handle.
U.S. Pat. No. 5,226,197 discloses a device for cleaning the tongue including a plurality of bristles and a semi-rigid scraper for removing debris from the tongue. The device is used in the same manner as a conventional toothbrush, and is moved anteriorly and posteriorly to scrape the tongue. (See col. 4, lines 35-50).
While these devices include means for cleaning the front of the tongue, they are incapable of cleaning the rear of the tongue without hitting the uvula and activating the gag reflex. In addition, tongue scrapers are unable to remove debris from the depressions and papillae in the tongue.
It has recently been found that stimulating the tongue, as by scraping or brushing, can accelerate the speech recovery process after a stroke. Attempting to brush or scrape with a conventional toothbrush or known tongue brushing methods is a long, tedious process which may be uncomfortable.
Accordingly, there is a long felt need for a tongue brush which is capable of effectively cleaning the entire tongue without activating the gag reflex, and it would be very desirable to have method of thoroughly cleaning or brushing a tongue with little discomfort.